Colorado Guy AF Ret.

If you don't like having the 20" wheels and tires on the A-Spec, I will show a pic of mine with 2018 TLX, 19" Black Diamond Cut wheels, with Michelin Premiere LTX, 255/50/19's. The outside daim. is exactly the same as
the 20's. Perfect fit, not issues.
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2019 RDX, A-Spec w/19" TLX Black Diamond Cut wheels

Colorado Guy AF Ret.

Having issues right now with downloading a pic. I'll get it done soon. Sorry.

Hou-RL

I noticed you mentioned that while you changed the tires and rims, the ride is still harsher than originally thought. It doesn't sound in reading a couple of your post that you benefited form the tires on the 19" comfort wise. What benefit is there to go form 20" to 19" tires and rims since the ride is still " harsh"?

Honda430

Looking forward to seeing your pictures. Bought a WDP Sh-awd Advance yesterday and while in the dealership it struck me that the TLX Black Diamond cut wheels would really compliment that color. Did you stick with the 235s or move up to 245 and if so what aspect ratio did you go with?

mode360

I see the pics located in the gallery: https://acurazine.com/g/album/10334259

Wander

The Michelin Premier LTX has a nice ride quality, but in size 255/50R19 that tire is available with a load index of 107. OEM Conti in 235/55R19 has a load index of 101. Michelin Premier LTX in 235/55R19 also has a load index of 101.

AFAIK other things being equal, a higher load index tire will tend to be stiffer ( more belt plies to permit higher max pressure ).

Colorado Guy AF Ret.

Thanks for that. I did have a conversation with The Tire Rack on why mine does ride rather harsh over poor roads and raised "ridges" and they said my tire was made to ride better for Crossovers and SUV's. But, your point might
be well taken. I'll have to look up the load rating of the OEM 20's to compare. I'll have to check also....is the 255/50/19 LTX rated only in 107?

But, as I'm sure you know, I had to go with that size to keep my diam. the same as the 20's.

Colorado Guy AF Ret.

I have an A-Spec. The OEM wheels/tires are 20". To keep the diameter the same I had to go with 255/50/19's. Otherwise you mess up lots of "systems" etc, if you don't stay real close to the OEM tire diameter.

My pics are in the upper section here under Wheels/Tires....etc...last one on that list. Also, my pics are on my Personal Info section, just click on my Log in name.
Or in the link below!

https://acurazine.com/g/album/10334259

Wander

The tire and wheel options were selected to keep the overall diameter the same. There is no difference in overall gearing, final drive ratios, or speedometer calibration between the different trims. This is an example of "+1" tire sizing.

235/55R19 is the same outer diameter. But not the same width, of course ( 235mm vs 255mm ). If you're willing to sacrifice some sporty appearance, you might get more ride comfort. I doubt you would notice much difference in performance unless you take your RDX to the track.

Sometimes a given size is available in more than one load rating, but I don't see that for this tire. The "XL" rating of 107 suggests this size is intended for a larger, heavier vehicle.

https://www.tirerack.com/tires/tiret....jsp?techid=55

From the press release, stock A-spec tires have a 101 load index. V is the speed rating. ( 149 mph )
A-Spec

• 20-in. alloy wheels
• 255/45R20 101V all-season tires

But I do suspect the A-spec has stiffer shocks and/or springs than the Base or Tech trims.

Colorado Guy AF Ret.

Yes, thank you for all your input. Much appreciated to have a meaningful "conversation" with a well knowing and interested participant here. I again, thank you for that.

And yes, Acura does say the suspension on the A-Spec is "tuned" differently...forgot the exact wording they used....but, bottom line, it is "stiffer" to be more of a sporting vehicle.

I am very aware of +1 sizing etc, I have done this many times...just older and yrs of doing this taught me some things. But, I did look up more on Load Ratings. It's really unclear, even with what Tire Rack has printed for our
"learning." I think only the tire engineers know the answers we want. Tires with low profiles, like 45 and less will have a lower Load Rating. From 50 series on up the load ratings can and normally do go up.
What's unclear, is just what the manufacturer does to make the 107 rated tire stronger than the 101 rated tire?? I've read where the # of plies does not necessarily increase but, that the composition of the materials used will
change in order to be rated higher and thus....a "stronger" tire.

Now, does that make the 107 rated tire a "harsher riding tire?" THAT's the million dollar question for me right now. And....IF there are any true "tire experts or engineers out there" that can answer this....many here would appreciate
an explanation.
My LTX rated at 107....and yes, I checked, there are no other Load Ratings for this tire...at least on Tire Rack.....does it make my A-Spec ride harsher than the stock 20's with a 101 Load Rating? That's the big question.
On the surface....many would say....oh, yes....look at the #'s....but, it's not that simple and easy to ascertain.

Yes, the diam. of the 2 tires I dealt with have the same diam,.crucial....but, yes, the 19's are slightly narrower in tread width when measured. And that's no big deal. My A-Spec handles great, turns in great, responds well to steering inputs, etc.
I'm not "canyon carving" or on a "road course" to see just what the A-Spec can do. But, that's not quite true of my TLX, A-Spec!! LOL. I have the Mich. A/S 3+'s on it, and they are great. Ride really well too....AND, they are
a Load Rated 107 tire. They are 45 series...and a Ultra High Performance Tire. So, I keep thinking..."why do they ride so well on my TLX??? Hmmmmm???

Now, again, the LTX were specifically designed for Crossovers and SUV's. So, that's our RDX's. Not the "wrong tire" for this vehicle. Tire Racks experience with testing "all tires" on their own tracks...is that the LTX rides better than
the A/S 3+ tires. So, they said they would swap them, since now the A/S 3+'s are available in 255/50/19's and are on their site, but, they said I would not be happier with the ride. So, I backed off.
Still, I'm not happy with my ride on rougher roads. And, I don't truly know IF it's because of the load rating is 107 compared to OEM's ratings of 101. I'm still trying to "drill down" on the issue.

Thank you...and if you can come up with real engineering help or someone else can, that would be great. I'd like to know IF...IF....I made a mistake, and not realizing that the 107 rated tires MIGHT...again, no one know for sure....MIGHT be contributing to my harsher ride. I cannot compare these to the OEM's 'cause I did not drive my new A-Spec with the 20's over rougher roads. Wish I had, then I'd know more about how they ride compared to
what I put on now. I passed all this on to my GM...who, yes, is my friend...and wants and asks for my feedback all the time. He will soon get an A-Spec for himself to drive. They are selling so fast he can't really grab one from
Inventory for his own use. He drives a TLX, A-Spec and an MDX.

catbert430

The stock tires for the Base, Tech, and Advance models are 235/55/19 101H Continental CrossContact LX Sport. They have a soft ride on my Tech in Comfort mode.

Perhaps if you swapped the Michelin Premier LTX 255/50/19 107H XL for 235/55/19 101H or 101V, they would soften your ride.
They are also cheaper.
I don't actually recommend switching out for Continentals because the Michelins have higher ratings.

The tires you have now are XL load rated and the other size is not. Still 29.2 diameter though. Perhaps a more comfortable ride.
I'm not an expert but, you might want to talk to TireRack about it.

Colorado Guy AF Ret.

You know...I may have vegged out at some point back when I was doing tons of research on tires, wheels, and other issues with the upcoming new RDX. After owning (3) Gen 2's. You may have a great point on the
235/55/19's. Although, the tread width would be a lot less than the 255/50's. I used to be a Conti guy, but, have gone back to Mich, even though they do cost more!
I found my old notes on tire sizing and diam. etc, I also looked at 235/60/18's....the same size as on the Gen 2 RDX's....and they are.....29.2"! Could have gone that route too....IF the wheel clears the rotors, calipers, suspension, etc..

Oh, just to clarify....and I've been reading all over the place to get ME some understanding....but, your Tech in Comfort mode does not do anything for the ride. Nor my A-Spec. It just changes the steering feel. Nothing else. IF I'm wrong on your Tech...show me where it states that. I KNOW my A-Spec, in Comfort Mode..ONLY adjusts the steering feel.
ONLY with the Advance is there a direct correlation between Comfort Mode and the settings of the dampers. Many on here are not understanding that.

I WISH my A-Spec had the suspension of the Advance...but, it does not.

But, I'd still like to know...for certain...that a 107 Load Rated tire WILL ride harder than a 101 rated tire. That issue is not conclusive...at least for me at this point.

Thanks again!!

Wander

I have no engineering expertise or contacts to throw at the problem, but anecdotally I got some Nokian Hakkapeliitta winter tires for my wife's 2014 MDX and she wanted pretty 19" wheels, so I got the 19s even though they were a higher load index than stock (107 vs 103 ), and they are noticeably stiffer. Fortunately, she likes a "sporty" ride.

Yes, I know winter tires can ride stiffer than all-seasons, but these are quite a bit stiffer than Blizzaks and Hakkas on our other vehicles.

I would NOT trade Michelin Premier LTXs for the Contis, in any size or any season. I'm actually hoping my Contis will wear out rapidly, and I will do everything in my power to facilitate that.

Wander

BTW, 18" wheels should work fine, if you wanted to go that route, and I'm even willing to bet 17" wheels will work. The compact spare wheel is 17". Unless I get motivated to buy some new winter wheels, I might try to reuse a 17" winter wheel and tire setup from a recently retired 2003 MDX. The tires are the right size and have minimal wear. I just need to find the right TPMS sensors. I guess if I'm bored this week, I could even grab one of those winter wheels and try a test swap. I'm pretty sure the dash will light up like a christmas tree without the TPMS sensor, but I can check clearance.

I have an Advance, so the big honkin "dynamic mode" dial does actually adjust the suspension. It's a bit subtle between "Comfort" and "Sport", IMO, but "Sport+" really is pretty sporty. In a good way.

But I think the "dynamic mode" does influence throttle response and transmission behavior in addition to steering assist, in all trims.

It may also have an effect on the aggressiveness of torque vectoring ( for SH-AWD ) and "agile handling assist". I seem to recall something on that in the copious pre-release 2019 RDX commentary. Unless I'm just fantasizing about some of the commentary on NSX.

catbert430

I'm with you.
According to all the reviews on Tire Rack, the Continentals wear out really fast.
I consider that a plus. Can hardly wait.

OTOH, they are making the same complaint against the Michelin Premier LTX.

I don't have a problem with tires wearing out in 30K miles. I don't usually keep them beyond 25K anyway.

Honda430

Wander

True on rapid wear of Michelin Premier LTX. My local Discount Tire shop even steered me away from them for that reason. I have gone to Michelin Defender LTX on other vehicles. They have a more "truckish" look, and they give up some wet grip in exchange for longevity, but they are good for snow and light off-road.

But I have the Premier LTXs on a vehicle that typically gets driven less, and they perform well. Quiet, solid handling, good in wet.

In addition to rapid wear, I was unimpressed with the snow performance of the Contis on a previous vehicle, and I had a problem with QC on a replacement set of Contis after the first ones wore out. Horrible highway vibration that no amount of balancing could fix. They finally figured out that one of more of the tires was out-of-round from the factory. Apparently, I'm not alone. Those tires are too darn expensive to deal with that crap.

catbert430

I had the DWS-06 on my TLX and thought they were awesome. Even good in moderate snow.
The dealer made my trade-in CPO and put a brand new set of the awful Goodyear LS2s on it.

I think you'll be well-pleased with the DWS-06. The TLX Berlinas are nice wheels as well.

catbert430

Thanks. I've seen several Tire Rack reviews of the Premier LTX where the reviewer recommended the Defenders instead.

Colorado Guy AF Ret.

I talked to one of the more senior tire techs at Tire Rack today and asked about the "ride difference" between a Load Rated tire of 107 vs one that has a 101 rating.

He said that in those ranges ride quality isn't an issue. It's when you get in to the "off road" type of tires that have more belts wrapped in the casing to give the tire a lot more strength, that you will then notice a
difference in ride quality.

So, I guess, the 107 rating of my LTX's vs the OEM tires rated at 101 doesn't really make my A-Spec ride any harder. I have to assume that it's just the stiffer suspension....or more directly the dampers are just "not very
forgiving on rougher roads."

So, those of you that have Advance models...you have the ability to soften those dampers....and I don't!! Which I wish I had. Oh well...we're always learning until........

Colorado Guy AF Ret.

I've been buying lots of tires for some time....many Contis and Michelins. It just seems like all owners are complaining about tire wear. No matter the brand or level of tire. My past problem with Contis was cracked sidewalls.
I gave up on them and went back to Mich. since their overall quality of build has a reputation of being much better than Contis. And, don't I know, that the Mich. are a lot more expensive than Contis. But, I feel I can trust the
Mich. more.

Wander

I'm quite puzzled about this, because the parts listings came up at Bernardi and the only difference in "suspension tuning" I see between A-spec and the other trims is a different part number for the rear springs. A-spec: 52441-TJB-A13 vs ( all other trims ) 52441-TJB-A03

Shocks, stabilizer bars, front springs, everything else is the same, except for the ADS ( electrically adjustable ) shocks on Advance.

I assume you dropped the air pressure a bit when you went to the 19" wheels with more tire volume?

Colorado Guy AF Ret.

Yes...tire pressure is the first thing I made sure of. And, Acura states the suspension is "different" my words, than the other models...??? Anyway....I know the dampers are different, since the Advance can change the compliance of
the damper by going to the Comfort mode. So, the A-Spec could just have reactive dampers that are just too harsh. So, those different rear springs could be stiffer, and I bet they are.

Anyone else with an A-Spec sense that on "rougher type roads and imperfections" that it rides harder than other RDX's you may have owned or driven?

Burger Steak & Eggs

I test drove the model with the adaptive dampers, wooden trim etc (Platinum Elite in Canada) and I found it to be smoother than the A-Spec. I can't recall what the dampers were set to in the Elite but I suspect they were at the default setting (Sport) as my sales person didn't seem at a high enough level to know about the adjustment. My best guess was the added smoothness was due to the smaller rims, and perhaps less firm rear spring as mentioned.

MI-RDX

I did not drive an A-Spec - just Tech and Advance. There is definitely a different 'road feel' between the 2 in the same mode on the same roads, and I'd suspect a more pronounced difference with the A-Spec if the rear springs are stiffer along with the lower profile tires. Hard to describe but the Advance just felt a bit more forgiving on irregular surfaces. It would have been nice to have had a couple of hours with each to become more familiar with the subtleties.